One, they lost her younger daughter, who was the apple of their eyes (at least her childhood pictures say so); secondly, they had to undergo a harrowing interrogation, followed by suspicion for the past 4 years.
Probably, today's verdict would bring them some peace-be it in their favour or against them.
No, we are not speaking in favour of anyone, but trying to analyse what was going through their minds then and what is going on now.
Considering that they have murdered their daughter (why they did so is a case that CBI has already answered), let us re-create what may have happened.
Seeing their daughter in an objectionable position with their household help Hemraj could truely have been beyond their imagination, given the amount of trust and faith that they had in her, perhaps. Add to it the fact that this is Haryana and not any other part of the country, honour killing is the most obvious thing that might have come spontaneously. And in a fit of rage, they hit her hard to have killed her. Could be non-intentional too.
Why Hemraj got killed, is a question that have several theories. One, he was caught with Aarushi and was also a victim of the Talwars' rage. A second theory could surely be what the CBI says. A cover up of the crime is a possibility. The Talwars, may have thought that by killing Hemraj, they can divert the suspicion of the police on the missing servant. And if he is murdered already, there would not be anyone to reveal the truth.
This is to remind the reader that trails of blood, indicating dragging of the body, were found on the terrace, further strengthening the theory that the Talwars' may have killed the servant.
Now, comes the interrogation part. For five years, the parents have been questioned about their murdered daughter and have been taken into custody several times without any concrete evidence. They have been asked questions that proved them guilty, but they probably had just one answer they knew was true.
Their personal lives were shattered, dragging Rajesh Talwar's involvement with other women and the couples' lifestyle. Again a circumstantial evidence, but not a concrete proof of a murder.
Imagine, their lives as doctors being juggled in public view, which may have reflected on their clinics and their social lives too. Life, for them has literally not been easy after losing their younger daughter.